Actuators typically are mechanical devices that are used for moving or controlling a mechanism, system or the like and typically convert energy into some type of motion. Examples of actuators can be found in any number of applications encountered in everyday life including automotive, aviation, construction, farming, factories, robots, health care and prosthetics, among other areas.
Mobile robotics and advanced prosthetics will likely play important roles in the future of the human race. Actuators frequently are used in these applications that enable movement of a robot or user arm or other appendage or item as desired.
Most existing mobile robots and advanced prosthetics, however, lack the strength and speed necessary to be effective. This is because they suffer from poor specific power (strength×speed/weight) which determines how quickly work can be done compared to another actuator of the same weight.
For example, if such devices are capable of lifting significant weight, they must do so very slowly, which inhibits their adoption for most applications. On the other hand, devices that can move more quickly are just not capable of handling anything more than the smallest weight.
Hydraulic and pneumatic power systems can be used with such actuators, among other power systems. Pneumatic power systems, however, have a relatively low operating pressure, which limits the amount of force they can impart and exhibit poor controllability due to the compressible nature of air, among other drawbacks.
Additionally, conventional hydraulics technology suffers from poor efficiency, noisy operation, high cost and maintenance challenges among other problems. These and other problems inhibit the use of hydraulics in many applications.